I think one of the many problems that Christianity faces is the lack of a systematic theology. There is no coherence across the religion and across the bible. The responsibility of this lies on the lap of an all powerful and system designing god. And this itself is incoherent with such a god as defined by Christians.
What I mean by this is a religion that has 32,000-42,000 denominations that argue to toss over different aspects of theology, different core beliefs and so on is, to me at least, an obvious indicator of an unsystematic theology. For the hope of salvation, if the idea existed at all, in the Old Testament, one had to adhere to a massive set of very strict rules. Now, overnight (with the death of Jesus) this set of rules is rendered completely irrelevant and salvation is suddenly achieved by entering into a loving relationship with a salvific Christ figure. Of course, even this notion of atonement has many different theories (ransom, penal substitution etc.) and shows the difficulty of coming to anything like a definite conclusion as to how and why anything happened as it did in Christianity.
The fact that you can argue to toss over whether the Creation story is symbolic or literal, or whether the Garden of Eden was real or symbolic, or real but representing the Temple of Jerusalem, again points to confusion. Virtually every idea in Christianity is up for grabs, arguable.
I could give a massive list of examples of lack of coherence across the religion and the bible, but you get the point. All things said, is an unsystematic theology that needs to be teased out via years of theology and biblical studies (and of which every point remains contestable) a fair representation of what an ideal religion would look like at the hands of an omni- god?
